Megan Fox: My Pregnancy Was So Rough I Thought I Was 'Maybe Birthing A Vampire Baby!'

Megan Fox is seen onstage during the 70th Annual Golden Globes Awards Nominations at the Beverly Hilton Hotel on December 13, 2012 in Los Angeles -- Getty Images

Megan Fox is the proud mom to baby Noah, who turns 3-months-old on Thursday, but she admitted her pregnancy was so rough, she related to what Bella Cullen went through in "The Twilight Saga."

"It was so bad for me, actually, that I felt like I was maybe birthing a vampire baby, like the one from 'Twilight,'" Megan joked during a visit to "The Tonight Show with Jay Leno" on Monday to promote "This is 40." "You know what happens to Bella -- where she's in like cold sweats all the time? I felt like that was happening, because I had no vitamins and nutrients. I was just nauseous."